1. Field of the Invention
The present invention relates generally to the field of document handling apparatus. More particularly, the invention relates to a printing plate transfer apparatus movable, in a novel manner, from a first horizontal plane input position to receive a plate from a first station to a second vertical and rotated plane output position for transferring the plate to a second station.
2. Description of the Prior Art
The present invention is directed generally to the printing field, and more particularly, to an offset printing system including, among other components, a platemaking section or station within which printing plates are produced, and a duplicating station, within which copies are made from the plate. In an automated printing system of this type it is also necessary to provide appropriate structure to automatically transfer the plate from the platemaking station to the duplicating station.
Frequently it happens that the plate is to be oriented differently in the duplicating station than it was in the platemaking station and, when this is the case, the transfer apparatus must be designed to turn or otherwise reorient the plate for receipt by the duplicating station. For example, in the particular system for which the present invention was developed, the transfer apparatus had to be capable of receiving a horizontally oriented plate from the platemaker and to then turn it to a vertical orientation while additionally rotating it by 90.degree. along the transporting axis for presentation to the duplicator.
In the prior art, a reorientation such as this is usually accomplished by means of a series of belts arranged in a tortuous path to carry the plate gradually into the desired orientation.
Such systems are obviously not fully adequate for a variety of reasons. For one thing, they require a substantial amount of space. Secondly, they tend to be quite expensive and add significantly to the total cost of the system. Furthermore, because they are designed to carry the plate along a fairly complex path requiring skewed rollers and the like, they are quite susceptible to jamming problems necessitating a system shutdown, and frequently warp, fray or otherwise damage the plate as well.